Final answer:
Comets are celestial bodies that slowly move across the sky and can be visible for extended periods, from weeks to months. They differ from planets with their unpredictable appearance times and can become visible as they vaporize near the Sun. Observing celestial objects, like comets, provides an understanding of their motion relative to Earth and the complexities of their paths.
Step-by-step explanation:
To much surprise, comets move across the sky slowly and are visible for large amounts of time. Comets, like the Moon and planets, wander among the stars, with their positions shifting slowly from night to night. Unlike the predictable orbits of planets, comets often appear at unpredictable times, which have historically sparked fear and superstition.
These celestial objects typically remain visible from a few weeks to several months as they reflect sunlight while they orbit the Sun. This visibility varies depending on factors such as their size, composition, and distance from the Sun at different points in their orbits. When a comet approaches the Sun in its elongated orbit, it heats up, causing its ice to vaporize and release gases and dust, creating a visible atmosphere and sometimes a tail that we can see from Earth.
One of the fascinating aspects of observing the sky is that during a single night, most celestial bodies seem to move with the entire celestial sphere, with the exception of meteors or 'shooting stars.' These brief events are caused by small pieces of cosmic dust burning up in the Earth's atmosphere, contrasting the otherwise apparent fixed positions of objects like planets and stars.